Material handling equipment



L. F. BLATT Oct. 31, 1967 MATERIAL HANDLING EQUIPMENT Filed Feb. 21, 1966 FIGB INVENTOR LELAND F. BLATT ATTORNEYS United States Patent Office 3,349,927 MATERIAL HANDLING EQUIPMENT Leland F. Blatt, Grosse Pointe, Mich. (24121 Mound Road, Warren, Mich. 48091) Filed Feb. 21, 1966, Ser. No. 528,844 3 Claims. (CI. 214-1) This" invention relates generally to material handling equipment, and more particularly, to a device for positioningand actuating a workpiece gripper.

In automatic handling equipment employing vacuum cups for gripping and transporting a panel-like workpiece, such as is used for loading a panel into and extracting it from a stamping press, it is desirable to have means for transporting the cup both longitudinally and vertically. This is desirable so that the removal of a configured panel from a die may be facilitated by the initial vertical lift of the panel from the die.

Accordingly, it is an object of this invention to provide means for traversing a gripping type vacuum cup in both the longitudinal and vertical directions and for actuating such a vacuum cup.

This and other objects of this invention will become apparent from the following'sp'ecification when considered in conjunction with the accompanying drawings.

In these drawings:

FIG. 1 is a simplified schematic view of the device of this invention;

FIG. 2 is a cross-sectional view of the vertical position controlling portion of this invention;

FIG. 3 is an exploded perspective view of the vacuum cup supporting structure;

FIG. 4 is a cross-sectional view of the vacuum cup and venturi structure.

Referring now to the drawings, the invention gen erally comprises a travel cylinder assembly and an actuator cylinder assembly 12 which together are suspended from hanger rod 13 and connected to a pivot arm 14 through universal joint 15. The assembly may thus be pivoted as desired through appropriate hydraulic cylinders or the like. The workpiece gripping is accomplished 'by a vacuum cup 16 which is mounted to the actuator cylinder assembly 12.

A travel cylinder piston 18 and piston rod 19 are mounted for reciprocal movement within the travel cylinder under the influence of differential fluid pressure applied to the opposed faces of piston 18. The advance stroke (toward the right as viewed in FIG. 1) of travel piston 18 is initiated by the admission of fluid pressure into the cylinder via advance line 20, While the return stroke (toward the left in FIG. 1) is initiated by the admission of fluid pressure to the travel cylinder via return line 22 which passes through hollow hanger rod 13 into the right hand portion of the travel cylinder. The admission of fluid pressure into these respective lines is controlled by travel cylinder control valve 24.

The actuator cylinder assembly 12 comprises an actuator cylinder body 26 which is rigidly connected to the right hand end of the travel cylinder piston rod 19, which protrudes from the travel cylinder. The entire actuator cylinder assembly thus reciprocates with travel cylinder piston rod 19. Actuator cylinder piston 28 and piston rod 30 are mounted for reciprocal movement within cylinder body 26 under the influence of differential fluid pressure applied to the opposed faces of piston 28. The advance (toward the right) stroke of piston 28 is initiated by the admission of fluid pressure through advance line 32, while the return (or leftward stroke) of actuator piston 28 is governed by return line 34. The admission of fluid pressure into these respective lines is governed by actuator cylinder control valve 36.

3,349,927 Patented Oct. 31, 1967 Rigidly secured to actuator cylinder body 26 is rack body 38. Rod pinion gear 40 and lift pinion gear 42 are rotatably mounted within rack body 38 so that no relative rotation occurs between the two pinion gears. Rod rack 44, which is an extension of actuator cylinder piston rod 30, engages rod pinion 40 and is reciprocally mounted in a longitudinal bore within the rack body. Lift rack 46 is in engagement with lift pinion 42, and is reciprocally mounted within a vertical bore in rack body 38.

Referring now to FIG. 3, in particular, vacuum cup assembly 48 is adjustably supported on the lower end of lift rack 46 by clamp 50. Cup assembly 48 comprises an arm 52 fixed to shaft 54 held by clamp 50. The angular relationship of cup mount 56 to arm 52 may be adjusted through radial serrations 58. The under surface of cup mount 56 is provided with a T-shaped slot 60. Into this slot is inserted cup insert 62, which is integrally molded into the vacuum cup 16. The upper face of insert 62 is provided with an O'-ring receiving recess 64 to establish the required seal between insert '62 and mount 56. The vacuum cup and cup insert assembly is retained within cup mount 56 by a retainer plate 66 and retaining screw 68, which screw also functions to maintain mount 56 and arm 52 in the desired angular relationship. The upper portion of insert 62 is provided with squared surfaces 69 to prevent rotation of cup 16 within respect to the supporting structure.

The interior of cup mount 56 is provided with bore 70 which is formed with a venturi portion 72. A venturi jet 74 is inserted into the left hand portion of bore 70, so that its exit is substantially at the throat of venturi 72. An air pressure line 76 (see FIG. 1) is threadedly connected to the left hand portion of bore 70, and the admission of air pressure to venturi jet 74 is governed by air pressure control valve 78 (see FIG. 1). When air pressure is applied to jet 74, an area of reduced pressure is created in the throat of venturi 72. This reduced pressure evacuates the interior of cup 16, which communicates with venturi 72 through passage 80 and bore 82.

In the normal sequence of operation for loading a panel into a stamping press, the device would be brought into position over the panel by pivotal movement of pivot arm 14 on any other movable or fixed support. Air pressure control valve 78 would then be actuated to supply air pressure through venturi 72 to create a vacuum within vacuum cup 16 and thereby establish a grip on the workpiece. Travel cylinder control valve 24 would then be actuated to drive travel cylinder 18 and piston rod 19 to the right to advance the workpiece into the press. Once this stroke had been completed, actuator cylinder control valve 36 would be actuated to drive piston 28 and rod 30 to the left to thereby lower lift rack 46 and cup assembly 48. This would seat the panel in the die of the press. The air pressure supply to venturi 72 would then be shut off by valve 78 to release the workpiece. The cup assembly 48 would then be withdrawn from the press by actuating valve 36 to lift cup assembly 48, and valve 24 to retract the gripper assembly from the press.

Following the operation on the workpiece in the press, the gripper assembly would once again be actuated to transport cup assembly 48 into the press, engage and grip the workpiece, lift and then withdraw the workpiece from the die, and release it in a desired location. The cycle would then be repeated with the next workpiece.

The desired sequencing of the valves could be automatically accomplished by a timer-operated series of cams which controlled a series of valve-operating solenoids.

This invention may be further developed Within the scope of the following claims. Accordingly, the above description is to be interpreted as illustrative of only a single operative embodiment, rather than a strictly limited sense.

I now claim:

1. In a material handling device utilizing inverted pliable cups for gripping a workpiece when a source of sub-atmospheric pressure is connected to the interior space within said cup, the improved cup traversing and supporting structure, which comprises:

a source of fluid pressure;

a first power cylinder;

fluid conduit means connecting said source of fluid pressure to said first power cylinder;

a first piston and piston rod reciprocable in said first power cylinder in response to the application of differential fluid pressure to the opposed faces of said first piston;

a second power cylinder fixed to said first piston rod and reciprocable therewith;

fluid conduit means connecting said source of fluid pressure to said second power cylinder;

a second piston and piston rod reciprocable in said second power cylinder in response to the application of differential fluid pressure to the opposed faces of said second piston;

said second piston rod being provided with gear teeth in the form of a rack gear;

means including a pinion gear in engagement with said piston rod rack gear and a second rack gear for converting the reciprocation of said second piston rod to a reciprocation of said second rack gear in a direction perpendicular to the axis of reciprocation of said first piston rod;

the vacuum cup being mounted on said second rack,

whereby actuation of said first and second power cylinders traverses said vacuum cup along two mutually perpendicular axes. 4

2. The device of claim 1 wherein means are provided for preventing relativ rotational movement between said vacuum cup and said second rack.

3. The device of claim 1 which further comprises a source of air pressure, a venturi, passage means connecting the interior of said vacuum cup to the throat of said venturi, and conduit means connecting said source of air pressure to said venturi, whereby a vacuum is generated in said vacuum cup by the flow of air through said venturi.

References Cited UNITED STATES PATENTS 2,867,185 1/1959 Hayward. 3,148,571 9/1964 Wallis 74426 3,260,376 12/1966 Stoll.

GERALD M. FORLENZA, Primary Examiner.

G. F. ABRAHAM, Examiner. 

1. IN A MATERIAL HANDLING DEVICE UTILIZING INVERTED PLIABLE CUPS FOR GRIPPING A WORKPIECE WHEN A SOURCE OF SUB-ATMOSPHERIC PRESSURE IS CONNECTED TO THE INTERIOR SPACE WITHIN SAID CUP, THE IMPROVED CUP TRAVERSING AND SUPPORTING STRUCTURE, WHICH COMPRISES: A SOURCE OF FLUID PRESSURE; A FIRST POWER CYLINDER; FLUID CONDUIT MEANS CONNECTING SAID SOURCE OF FLUID PRESSURE TO SAID FIRST POWER CYLINDER; A FIRST PISTON AND PISTON ROD RECIPROCABLE IN SAID FIRST POWER CYLINDER IN RESPONSE TO THE APPLICATION OF DIFFERENTIAL FLUID PRESSURE TO THE OPPOSED FACES OF SAID FIRST PISTON; A SECOND POWER CYLINDER FIXED TO SAID FIRST PISTON ROD AND RECIPROCABLE THEREWITH; AND RECIPROCABLE THEREWITH: FLUID CONDUIT MEANS CONNECTING SAID SOURCE OF FLUID A SECOND PISTON AND PISTON ROD RECIPROCABLE IN SAID SECOND POWER CYLINDER IN RESPONSE TO THE APPLICATION OF DIFFERENTIAL FLUID PRESSURE TO THE OPPOSED FACES OF SAID SECOND PISTON; SAID SECOND PISTON ROD BEING PROVIDED WITH GEAR TEETH IN THE FORM A RACK GEAR; MEANS INCLUDING A PINION GEAR IN ENGAGEMENT WITH SAID PISTON ROD RACK GEAR AND A SECOND RACK GEAR FOR CONVERTING THE RECIPROCATION OF SAID SECOND PISTON ROD TO A RECIPORCATION OF SAID SECOND RACK GEAR IN A DIRECTION PERPENDICULAR TO THE AXIS OF RECIPROCATION OF SAID FIRST PISTON ROD; THE VACUUM CUP BEING MOUNTED ON SAID SECOND RACK, WHEREBY ACTUATION OF SAID FIRST AND SECOND POWER CYLINDERS TRAVERSES SAID VACUUM CUP ALONG TWO MUTUALLY PERPENDICULAR AXES. 